Laars FT Series, Instructions Manual

Page: 17 / 32

Page 17
Cascading the FT Series ‘Heating Only’ Boiler
Line
V
oltage T
erminals
Low
V
oltage T
erminals
R 0-1
0V W
(+) INPUT (-)
LWC
O/S
T/T
AC24V
OUTPUT
DHW
TEMP.
SENSOR
Low
V
oltage T
erminals
DHW
P
UM
P
N G
L N G
SYSTEM
P
UM
P
L N G
MAIN POWER
(14 Gauge Wire)
L/ZC
L-T/T
P
UM
P
N G
L/ZC
L-T/T
CASCADE
SYSTEM
SENSOR
Line
V
oltage T
erminals
Low
V
oltage T
erminals
2-stage aquastat
part # RE09320
R 0-1
0V W
(+) INPUT (-)
LWC
O/S
T/T
R B W
AC24V
OUTPUT
DHW
TEMPERATURE
SENSOR
Low
V
oltage T
erminals
DHW
P
UM
P
N
G
L
N
G
SYSTEM
P
UM
P
L
N
G
MAIN POWER
(14 Gauge Wire)
L/ZC
L-T/T
P
UM
P
N
G
L/ZC
L-T/T
CASCADE
SYSTEM SENSOR
INPU
T
1
2
0
V
OL
T
C
IRCULA
T
OR
S
X
X
E
N
D
S
W
IT
C
H
Z
C
1
2
0
V
RE
L
A
Y
FU
S
E
1
AM
P
SL
A
V
E
MA
S
TE
R
1
23
4
Z
O
NE
4
PR
IOR
IT
Y
O
N
OF
F
PO
W
E
R
ZO
N
E
2
ZO
N
E
3
FOU
R
ZONE
S
W
ITC
H
IN
G
RELA
Y
W
ITH OPT
IO
N
AL PR
IOR
IT
Y
PL
U
G-
IN CAR
D
S
R
E
SET N
O
RMA
L
S
R
5
0
4
-E
X
P
T
'S
T
AT
S
ZO
N
E
1
ZONE
3
PO
W
E
R
ZONE
1
ZONE
2
Z
R
Wiring Diagram for Cascaded
Reverse Return with Zone Pumps and Indirect
P4
DHW
Aquastat Stage 1
(18 Gauge Wire)
P3
P2
P1
Line
V
oltage T
erminals
Low
V
oltage T
erminals
R 0-1
0V W
(+) INPUT (-)
LWC
O/S
T/T
AC24V
OUTPUT
DHW
TEMPERATURE
SENSOR
Low
V
oltage T
erminals
DHW
P
UM
P
N
G
L
N
G
SYSTEM
P
UM
P
L
N
G
MAIN POWER
(14 Gauge Wire)
L/ZC
L-T/T
P
UM
P
N
G
L/ZC
L-T/T
CASCADE
SYSTEM SENSOR
Optional External Low Water Cutoff
(Factory Jumper Installed)
Optional External Low Water Cutoff
(Factory Jumper Installed)
Optional External Low Water Cutoff
(Factory Jumper Installed)
Outdoor Sensor (18 Gauge Wire)
Cascade System Sensor (18 Gauge Wire)
DHW
Aquastat Stage 2
(18 Gauge Wire)
Power to 24V
Transformer
(14 Gauge Wire)
Power to 24V
Transformer
(14 Gauge Wire)
Power to 24V
Transformer
(14 Gauge Wire)
Floor M
odel B
oiler 1 (L
ead)
Floor M
odel B
oiler 2 (F
ollo
w)
Floor M
odel B
oiler 3 (F
ollo
w)
NOTE: The terminal blocks ar
e NOT the same on
the floorstanding VS the wall-mounted models! See Section 1.D on page 5
Generic Pump Controller
Figure 17.
Wiring diagram for cascaded reverse return
with zone pumps and indirect.